The essence that is not an essence. Universally unloved, the flaws in wine are as insidious as they are unwanted, and come in many forms. The sharp vinegar and acetone tang of volatile acidity; the rotten eggs reduction; the overly nutty or balsamic note of oxidation; the sweaty socks, garlic and stinky cheese of mercaptans; the wet dog or manure of brettanomyces yeast; and yes, the all-too-common wet cardboard or wet band-aid aroma of cork taint. All too be avoided rather than celebrated. But knowing the difference between a faulty bottle and a wine that you just don’t like remains harder than you might think. Levels of sensitivity to these compounds vary among individuals, and to make matters worse, in tiny amounts they don’t always ruin a wine. A modicum of volatile acidity and brettanomyces are even coveted by some winemakers (and their customers) as a distinct element of either their terroir or their intended style. One drinker’s rustic wine is another’s sewer of bacteria, or so it seems. Learning to recognize these flaws is a useful skill for anyone who enjoys wine, but this proves not so easy to do outside of a classroom. Serious students of wine should spend at least one afternoon subjecting themselves to sometimes-gag-inducing levels of these delightful monsters at some point in their careers. Know thine enemy, or so the saying goes.
You didn’t really expect me to recommend faulty wines, did you?
Pay attention to how your wines smell and taste, and never pass up the opportunity to smell and taste a little of a wine that someone around you has identified as flawed. The more exposure you get to such wines, the more you will be able to spot them on your own. My personal experience is that my sensitivity to cork taint in particular has dramatically increased over time, and I know others who have experienced the same.
Most wine education programs will include a session on wine faults, which can be invaluable for anyone looking to experience the range of things that can go wrong in a wine. I highly recommend these experiences.